Dictionary.com defines jargon like this:
1. jargon: -noun, the language, esp. the vocabulary, peculiar to a particular trade, profession, or group: medical jargon.
It also defines jargon like this:
2. jargon: -noun, unintelligible or meaningless talk or writing; gibberish.
Joomla!'s roots go back a few years, and it definitely has a language all its own. Seasoned veterans are fluent in Joomla! jargon, but for "newbies", that second definition is probably the most appropriate definition for what Joomla! jargon really is. For that reason, I have decided to attempt to compile a list of the most commonly used words and/or phrases in Joomla!, and give them a definition that actually means something to a non-veteran Joomla! user.